This invention relates to an apparatus for estimating a motion vector of a video signal.
A motion compensation technique is used in processing a video signal for data compression. In general, such a motion compensation technique requires an apparatus for estimating a motion vector of a video signal.
Some motion vector estimating apparatuses use a block matching method. In the block matching method, a frame of a video signal is divided into a plurality of blocks, and the blocks of a current frame and the blocks of a preceding frame are compared in pixel data values to estimate a motion vector.
In prior art motion vector estimating apparatuses of the block matching type, under conditions where parts of an image or a frame have different motions respectively, as the size of blocks is decreased, a resultant motion (a total motion) is estimated more accurately. On the other hand, as the size of blocks is decreased, the estimation of a motion is more easily affected by noises.